I have a mobile application that needs its backend wired up so it can finally start exchanging real data. The app targets both iOS and Android, and the current front-end screens are already in place—I just need the underlying connections set up. Here’s what I’m after: • Connect the app to Firebase (authentication, real-time / Firestore database and basic cloud functions). • Hook up any existing REST endpoints so data flows cleanly in and out of the app. • Provide clear, commented code and a short “how to” README so I can re-point the build or extend endpoints later. Keep the work focused on getting a reliable, working link between the UI and backend—no major refactors or design changes needed. If you have experience integrating Firebase alongside additional APIs in a cross-platform setup, this should be a straightforward assignment.